{"product_id":"icp-control-board-for-wph4424000rkb1-oem-circuit-board-ships-today-1","title":"ICP Control Board for WPH4424000RKB1 — OEM Circuit Board | Ships Today","description":"\u003ch3\u003eOverview\u003c\/h3\u003e\u003cp\u003eThis genuine OEM control board (part #1178001) is the electronic brain of the ICP\/Tempstar\/Heil WPH4424000RKB1 heat pump. It manages defrost timing, reversing-valve operation, compressor and fan sequencing, time delays, and safety lockouts based on inputs from the thermostat and sensors. When the board fails, the unit may not start at all, skip defrost (causing outdoor coil icing), short-cycle, run the fan or compressor continuously, or throw erratic fault codes. Power surges, moisture, corroded relays, and burned traces are common causes. Installing the correct OEM board restores reliable sequencing and protects the compressor from improper cycling.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eSpec\u003c\/th\u003e\n\u003cth\u003eValue\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003ePart Number\u003c\/td\u003e\n\u003ctd\u003e1178001\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eType\u003c\/td\u003e\n\u003ctd\u003eDefrost \/ Control Circuit Board\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eICP (Tempstar \/ Heil)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eApplication\u003c\/td\u003e\n\u003ctd\u003eHeat Pump Outdoor Control\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003ch3\u003eCompatibility\u003c\/h3\u003e\u003cp\u003eDirect OEM replacement for the ICP\/Tempstar\/Heil WPH4424000RKB1. Match the board part number and connector layout to your existing board before installing — control boards are model-specific.\u003c\/p\u003e\u003ch3\u003eInstallation Guide\u003c\/h3\u003e\u003col\u003e\n\u003cli\u003e\n\u003cstrong\u003eSafety First\u003c\/strong\u003e — Disconnect power at the disconnect and breaker; verify zero voltage with a multimeter.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAccess\u003c\/strong\u003e — Remove the electrical\/control access panel.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDocument\u003c\/strong\u003e — Photograph every connector and wire position before unplugging anything.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRemove\u003c\/strong\u003e — Unplug the harnesses, release the standoffs\/screws, and lift out the old board.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall\u003c\/strong\u003e — Mount the new board on the same standoffs and reconnect each harness exactly per your photo.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest\u003c\/strong\u003e — Restore power, run a heat and cool call, and confirm proper sequencing and defrost operation.\u003c\/li\u003e\n\u003c\/ol\u003e\u003ch3\u003eSigns You Need a Replacement\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eUnit completely dead with 24V present at the board\u003c\/li\u003e\n\u003cli\u003eOutdoor coil ices up (no defrost cycle)\u003c\/li\u003e\n\u003cli\u003eCompressor or fan short-cycles or won't sequence\u003c\/li\u003e\n\u003cli\u003eVisible burn marks, corrosion, or melted relays on the board\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eShipping \u0026amp; Returns\u003c\/h3\u003e\u003cp\u003eShips same day before 3 PM CST. 30-day returns. Backed by the National HVAC Parts fitment guarantee.\u003c\/p\u003e","brand":"ICP","offers":[{"title":"OEM","offer_id":63027203211635,"sku":"1178001","price":214.44,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":63047469433203,"sku":"1178001-GEN","price":164.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-control-board-furnace-1178001_06b895a7-ac7d-4dc4-86a1-b94514e9a97a.jpg?v=1782885566","url":"https:\/\/nationalhvacparts.com\/products\/icp-control-board-for-wph4424000rkb1-oem-circuit-board-ships-today-1","provider":"National HVAC Parts","version":"1.0","type":"link"}